Patent GB-839385-A (GB)
Title: Improvements in circular knitting machines equipped with wrap thread mechanism
Inventor: SAUNDERS ALFRED PERCY
IPC: D04B9/10
Filed: 1957-01-28
Abstract: 839,385. Knitting-machines. WILDT & CO. Ltd. Jan. 23, 1958 [Jan. 28, 1957], No. 2962/57. Class 74 (2). Wrap instruments 6, which extendin an axial direction within the upper cylinder of a superposed cylinder machine, are maintained when inoperative at a lower height H with their yarn guiding extremities -withdrawn within - the needle circle, and are raised, when required to feed wrap yarns to the needles, to an upper height H<SP>1</SP>. 'The wrap instruments-are housed in a grooved cylindrical bed 7 extending within the upper needle cylinder so as to provide an annular gap between the bed and the inner wall of the upper cylinder to provide space for the removal of a wrap instrument when desired as described in Specification 839,384. As described in a twofeeder machine, wrap patterning is achieved by positioning all of the needles in the bottom cylinder at wrap height L prior to the first feeding station F so as to receive wrap yarns at a wrapping station W from selected wrap instruments -which have been raised to their operative height H<SP>1</SP> by selectors 25 of a bank positioned before the wrapping station W. To facilitate their selection by the selectors the instruments are provided with frangible tooth butts 13. After feeding their wrap yarns to the -needles 'the selected instruments are lowered to their inoperative position by a return cam 40 which engages a butt 12 on the instruments for this purpose and which butt 12 then rides on a levelling cam 28 to support the -instruments at their inoperative height H. The needles operated by their sliders in the bottom cylinder then pass through the cams at the first feeding station F whereafter only selected needles are raised to wrapping height to receive yarn from the wrap instruments at the next wrapping station W<SP>1</SP> prior to the second feeding station F<SP>1</SP>. Needle selection is obtained by the provision of jacks 33<SP>1</SP> having frangible tooth butts 35 and positioned in the bottom cylinder to engage the bottom sliders '4 when selectively raised by a selector 34<SP>1</SP> of a bank positioned adjacent the bottom cylinder. All of the wrap instruments are raised to their operative height H<SP>1</SP> prior to 'the wrapping station W<SP>1</SP> by a cam 32 which engages the butts 12. The selected needles are, therefore, wrapped at wrapping station W<SP>1</SP> by the corresponding wrap instruments and then pass through the cams of the second feeding station F<SP>1</SP>. Withdrawable bolt -cams 47 are provided immediately after the bank of selectors 25 and the cam"32 so as to enable when desired the selections of wrap instruments to be neutralized so as to prevent them actually feeding their wrap yarns at the wrap stations W and W<SP>1</SP>. in the case of a half-hose machine the butts 12 may be of two different lengths corresponding to the instep and heel needles whereby all round patterning can be changed to half-round patterning without necessitating any alteration in the operation of the selectors 25. The cam system at each wrapping station comprises inner and outer cams 42, 43 suitably profiled for effecting the wrapping movement ofthe instruments. The -upper -end of each wrap instrument is formed with a butt portion 10 with a rearwardly extending lip 10b. Normally when the instruments-are inoperative or their lower height the lips 10b engage-a circumferentially extending cam 41 which holds the instruments -withdrawn -within the needle circle. When the -instruments are -raised to their operative height, the lips 10b pass and engage above the inner cam 42 so that the butts 10-pass between the two cams 42, 43 and are -guided -thereby. A leading portion 42a of each cam 42 is bevelled to permit the lips of the butts of selected instruments to pass up over the cam 42, and a gap 48 is also provided in each cam 42 to permit the lips 10b to pass beneath the cam 42 when the corresponding instruments are lowered to their inoperative position by cam 47. Sinkers 23, additional to the usual arcuate-sinkers in the lower cylinder, are provided in the top cylinder in lieu of the top cylinder verge and are controlled by a sinker cam system 24 in the top cam box. Shogging mechanism for shogging the bed 7 are or more times in one direction or the other is provided and is of the character described in Specification 455,801. Specification 522,901 also is referred to.